Overdubbing device

ABSTRACT

A CPU of an overdubbing device plays back a music file recorded in a memory card of the device and outputs the file as a played-back audio signal while mixing the played-back audio signal with an external audio signal input from the outside, to thus perform overdubbing. A music file recorded through overdubbing last time is automatically set as a playback music file for the next time, and a selected state of means for selecting execution/nonexecution of overdubbing is maintained as the state of execution. As a result, overdubbing is enabled by twice operations of a record key, whereby the operation is made identical with operation performed during ordinary recording.

PRIORITY INFORMATION

This application claims priority to Japanese Patent Application No.2008-005588 filed on Jan. 15, 2008 which is incorporated herein byreference in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to an overdubbing device and, moreparticularly, to a device that plays back a recorded music file, to thusoutput a played-back audio signal, and that records the played-backaudio signal while mixing it with an external audio signal input fromthe outside.

2. Related Art

There has hitherto been put forward an overdubbing apparatus that playsback a recorded music file, to thus output a played-back audio signal,and that records the played-back audio signal while mixing it with anexternal audio signal input from the outside.

For instance, JP 7-85593 A discloses an overdubbing function of readingaudio data recorded in a recorder and writing mixed audio data back intothe recorder by use of a buffer.

JP 2003-66999 A discloses an overdubbing function of mixing an audiosignal input from a microphone with an MP3 audio signal of a source filein a memory card, storing a resultant mix as a mixed file in the memorycard, and utilizing the mixed file as a new source file from the nexttime.

JP 2004-157260 A discloses an overdubbing function of repeatingoperation for mixing an input audio signal with a source file in amemory card, to thus create a first mixed file, and mixing the firstmixed file taken as a new source file with an input audio signal, tothus create a second mixed file.

However, the related-art device encounters problems stemming fromcomplication of operation, such as a necessity for operation formanually selecting a source music file (a source file) used whenoverdubbing is performed, a necessity for special key operation forperforming overdubbing (e.g., a MIX key). In particular, whenoverdubbing is repeatedly performed, it is necessary to repeatedlyperform the special operations; hence, complication becomes noticeable.

SUMMARY

The present invention provides a device that performs overdubbing bysimple operation; particularly, a device that enables considerableenhancement of user's operability when overdubbing is repeatedlyperformed.

An overdubbing device of the present invention plays back a recordedmusic file, outputs a played-back audio signal, and records theplayed-back audio signal while mixing the played-back audio signal withan external audio signal input from the outside. The device of thepresent invention has a setting unit that sets a recorded music file asa playback music file for the next time; a selection unit that is a unitfor selecting execution/nonexecution of overdubbing and that maintains aselected state of execution of overdubbing when overdubbing wasperformed last time; and a recording unit that plays back the playbackmusic file in response to operation of a record key and a state of theselection unit, to thus perform overdubbing.

In an embodiment of the present invention, the overdubbing device has anormal recording mode for recording only the external audio signal inputfrom the outside in addition to the overdubbing mode. The recording unitshifts to a record standby state by first operation of record key andperforms recording by second operation of the record key in the normalrecording mode; and shifts to a record standby state by the firstoperation of the record key and plays back the playback music file bysecond operation of the record key in the overdubbing mode, to thusperform overdubbing by the same operation as that performed in thenormal recording mode.

According to the present invention, overdubbing is performed by simpleoperation. In particular, when overdubbing is repeatedly performed,user's operability can be significantly enhanced.

The invention will be more clearly comprehended by reference to theembodiment provided below. However, the following embodiment is a mereillustration, and the scope of the invention is not limited to theembodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described indetail by reference to the following drawings, wherein:

FIG. 1 is a block diagram showing the configuration of a portableoverdubbing device of an embodiment;

FIG. 2 is a processing flowchart of the embodiment;

FIG. 3 is a view showing a screen display for selecting a file to beplayed back;

FIG. 4 is a view showing a playback screen display;

FIG. 5 is a view showing a screen for selecting whether or not toperform overdubbing;

FIG. 6 is a view showing a screen display appearing during overdubbing;

FIG. 7 is a view showing a playback screen display appearing at the endof overdubbing; and

FIG. 8 is a block diagram showing the internal configuration of a CPU.

DETAILED DESCRIPTION

An embodiment of the present invention will be described hereunder byreference to the drawings.

An overdubbing device of the present embodiment is a portableoverdubbing device; specifically, a stereo overdubbing device having abuilt-in microphone. The portable overdubbing device has variousoperation keys. The operation keys include a record key (a REC key), akey for playing back a recorded music file (a PLAY key), a key forstopping recording/playing back operation (a STOP key), a menu key foractivating a menu, a dial key for performing settings or changing, andothers. Further, the portable overdubbing device has a display, such asan LCD and an organic EL, and displays various setting conditions andrecording/playing-back conditions.

FIG. 1 shows a block diagram showing the configuration of a portableoverdubbing device. A dial key 10, an LCD 12, an operation key 14 areprovided on the front of the device. The dial key 10 is for selecting amusic file to be played back and selecting whether or not to performoverdubbing. The operation key 14 includes the record key, the playbackkey, the stop key, and the menu key as mentioned previously. Anoperation signal from the dial key 10 and the operation key 14 issupplied to a CPU 18.

An audio signal from the outside is input to an input terminal (AUDIOIN) and supplied to a codec (CODEC) 16. The codec 16 converts theexternal audio signal into a digital signal, to thus encode the signal,and supplies the thus-encoded signal to the CPU 18. The CPU 18 writesthe external audio signal data as a music file into a memory card 30loaded in a card socket 28. The data may also be compressed as an MP3file. The CPU 18 operates by means of a clock signal from a system clock19 and performs signal processing by using RAM 20 as working memory inaccordance with a program previously stored in ROM 22. In particular,the CPU 18 stores a state of execution/nonexecution of overdubbing inthe RAM 20. In a default state achieved immediately after activation ofpower, there is a state of nonexecution of overdubbing, and a useroperates the operation key 14, thereby arbitrarily selecting executionor nonexecution of overdubbing. The CPU 18 stores the currently-selectedstate in the RAM 20. The CPU 18 also reads a music file recorded in thememory card 30, expands the compressed music file, and supplies the fileto the codec 16. The codec 16 decodes the music file, converts thethus-decoded file into an analog signal, and outputs the signal from anoutput terminal (AUDIO OUT). During overdubbing operation, a music filerecorded in the memory card 30 is played back; mixed with an externalaudio signal, such as music of the guitar, vocals, and the like, inputfrom the input terminal; and output as a music signal. The CPU 18 writesthe thus-mixed music signal data as a music file into the memory card30. When written into the memory card 30, the music file is impartedwith a file name different from that of the played-back music file (asource file). FIG. 8 shows a functional block diagram of the CPU 18. Themusic file played back from the memory card 30 is stored in the buffermemory 29 and supplied to a mixing unit 18 a of the CPU 18. The mixingunit 18 a captures the external audio signal; adds the thus-capturedsignal to the played-back music signal; supplies the thus-added signalto the codec 16 and outputs as a music signal; stores the signal intothe buffer memory 29; and further writes the signal into the memory card30. In addition to including the mixing unit 18 a, the CPU 18 has a partcancellation unit 18 b for removing a specific signal included in theplayed-back music signal and a controller 18 c for controlling aplayback speed achieved during playing-back and recording operation.

The respective units of the portable overdubbing device operate uponreceipt of power supply from a battery 24. The battery 24 becomesrecharged by means of power from a power circuit 26.

In such a configuration, the CPU 18 selectively performs recording(normal recording), overdubbing, and playback in accordance withoperation of the operation key 14. However, when overdubbing isperformed, a music file to be played back is first selected by operatingthe dial key 10; a selection as to whether or not to perform overdubbingis made; and the record key is operated. Thus, operations are intricate.Therefore, the CPU 18 of the present embodiment performs processingprovided below to simplify user's operation required during overdubbing.First, when recording or overdubbing is performed, a recorded music fileis automatically set as a music file for the next playback. When themusic file is automatically set as a playback music file for the nexttime, the user does not need to select a music file (a source file) tobe played back when the user performs overdubbing operation next time.“Automatic setting” means setting a default playback state for the musicfile or setting the music file in a playback standby state. The playbackstandby state means that a music file is automatically played back whena key is operated next time. Second, when overdubbing is performed, thestate of execution/nonexecution of overdubbing is held, as it is, in thestate of execution. Operability is considerably enhanced by performingthese processing operations. Specifically, when overdubbing is repeated,a music file recorded by previous execution of overdubbing isautomatically set as a playback music file, thereby saving the user fromselecting a source file. Moreover, the state of execution of overdubbingis held as it is, which saves the user from again selecting execution ofoverdubbing. As a result of the efforts being saved, even whenrepeatedly performing overdubbing, the essential requirement for theuser is to perform only the same operation as that performed duringnormal recording operation.

FIG. 2 shows a processing flowchart of the present embodiment. First,the user operates the dial key 10 to select a music file to be playedback (S101). FIG. 3 shows an example playback file selection screendisplayed on the LCD 12 by the CPU 18. The example is a case where fourmusic files are recorded in the memory card 30. An “A.WAV” file amongthe four music files is highlighted, showing that the file is currentlyselected. When selection of a playback music file is completed, the CPU18 then displays a playback screen on the LCD 12 (S102). FIG. 4 shows anexample of a playback screen displayed on the LCD 12 by the CPU 18. Thename of a file to be played back is displayed along with a timeindication. The playback screen shows a file remaining in a playbackstandby state, and the drawing shows that the selected “A.WAV” file isin a playback standby state. When the record key (REC key) is operatedin this state (first operation of the record key: S103), processingproceeds to a record standby state. The CPU 18 determines whether or notthe dial key 10 is operated in the record standby state (S104).Overdubbing is set in a nonexecution mode in a default state achievedimmediately after activation of power. At the time of first overdubbing,execution of overdubbing must be selected; hence, the user operates thedial key 10 to select execution of overdubbing. When execution ofoverdubbing is selected, the CPU 18 stores the state in the RAM 20 andmaintains the state until a change is made to the current state (S105).FIG. 5 shows an example screen for selecting execution/nonexecution ofoverdubbing. Execution (ON)/nonexecution (OFF) of overdubbing (OVERDUB)is displayed, and execution is highlighted, to thus show that executionis currently selected.

When the user again operates the record key (REC key) in this state(second operation of the record key: S106), the CPU 18 determineswhether the state of overdubbing is execution or nonexecution (S107).Since the state of overdubbing is stored in the RAM 20 and set toexecution, a determination is made as YES, and overdubbing is commenced.Specifically, the CPU 18 reads the selected “A.WAV” file from the memorycard 30; plays back the file; and outputs a played-back signal as aplayed-back music signal from an output terminal (S108). The played-backsignal is mixed with an external audio signal by a mixing unit 18 a inthe CPU 18. The thus-mixed music signal data are written in the memorycard 30 as a music file with another file name; for instance, “X.WAV”(S109). FIG. 6 shows an example screen appearing during overdubbingoperation. A file name of a music file (a source file) being played backand a file name of an overdubbed music file are displayed along with atime indication. Overdubbing is performed until the user operates thestop key. Nonexecution of overdubbing, which is the default stateachieved immediately after activation of power, is kept unless the useroperates the dial key 10. In S107, the CPU 18 determines thatoverdubbing is in a nonexecution state and only performs recording ofthe external audio signal without playing back the “A.WAV” file.

When the user operates the stop key (S110), the CPU 18 stops overdubbingoperation and again displays the playback screen on the LCD 12 (S111).FIG. 7 shows an example playback screen. A file name of the music file“X.WAV” recorded in the memory card 30 by means of overdubbing isdisplayed, and the file is set in a playback standby state. It should benoted that the “X.WAV” file is set in a playback standby state in spiteof the fact that the user did not perform operation for selecting afile. Processing pertaining to S103 and subsequent steps is repeated.

When the user operates the record key (REC key) in this state, the CPU18 determines whether or not the dial key 10 is operated (S104). Sinceexecution of overdubbing has already been selected by previous operationof the dial key 10 and the state is maintained, the user does not needto operate the dial key 10 when performing overdubbing again. When theuser further operates the record key (REC key) in this state (S106), theCPU 18 again determines the state of execution/nonexecution ofoverdubbing (S107); makes a determination as YES; and starts playingback a music file (S108). The file played back at this time is the“X.WAV” file set in the playback standby state in S111.

In the meantime, when the user performs normal recording operationrather than overdubbing operation, the user operates the record Key, tothus shift the device to a record standby state. After confirming thatoverdubbing is set in a nonexecution state (the nonexecution state isselected by operating the dial key 10 when overdubbing is set in anexecution state), the record key is again operated, to thus performrecording.

As mentioned above, at the time of first overdubbing, execution ofoverdubbing must be selected by operating the dial key 10. However, whenoverdubbing is repeatedly performed, the state of execution/nonexecutionof overdubbing is maintained as-is; hence, the user does not need tooperate the dial key 10 anew. Moreover, since the music file recordedthrough previous overdubbing is automatically set in the playbackstandby state, the user does not need to select the source file at thetime of execution of overdubbing. As is seen from the flowchart shown inFIG. 2, operation to be performed when second or subsequent overdubbingoperation is carried out includes only operation of the record key (RECkey) performed in S103 and operation of the record key (REC key)performed in S106. These operations are totally identical with theoperations performed during ordinary recording that is not overdubbing.Specifically, when repeatedly performing overdubbing, the user performsoperations that are completely identical with those performed forordinary recording operation.

1. An overdubbing device that plays back a recorded music file, outputsa playback audio signal, and records the played-back audio signal whilemixing the played-back audio signal with an external audio signal inputfrom the outside, the device comprising: a setting unit that sets arecorded music file as a playback music file for the next time; aselection unit that is a unit for selecting execution/nonexecution ofoverdubbing and that maintains a selected state of execution ofoverdubbing when overdubbing was performed last time; and a recordingunit that plays back the playback music file in response to operation ofa record key and a state of the selection unit, to thus performoverdubbing.
 2. The overdubbing device according to claim 1, furthercomprising: a normal recording mode for recording only the externalaudio signal input from the outside in addition to the overdubbing mode,wherein the recording unit shifts to a record standby state by firstoperation of record key and performs recording by second operation ofthe record key in the normal recording mode; and shifts to a recordstandby state by the first operation of the record key and plays backthe playback music file by second operation of the record key in theoverdubbing mode, to thus perform overdubbing by the same operation asthat performed in the normal recording mode.
 3. An overdubbing devicehaving an ordinary recording mode for recording only an external audiosignal input from the outside and an overdubbing mode for playing back arecorded music file, outputting the file as a played-back music signal,and recording the played-back music signal while mixing the played-backmusic signal with the external audio signal input from the outside, thedevice comprising: a selection unit that selects execution/nonexecutionof overdubbing and that maintains a selected state of execution ofoverdubbing when overdubbing was performed last time; and a setting unitthat automatically sets a music file acquired through overdubbing as aplayback music file for the next overdubbing operation, wherein secondand subsequent overdubbing operations after first overdubbing operationbecome identical with those performed in the normal recording mode bymeans of maintenance operation of the selection unit and settingoperation of the setting unit.